US6146959A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of forming capacitors containing tantalum

Assignee: Micron Technology Inc

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Filing: 1998-06-15

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Granted: 2000-11-14

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Expires: 2018-06-15

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Abstract

Abstract The invention pertains to methods of forming capacitors and semiconductor circuit components. In one aspect, the invention includes a method of forming a dielectric layer comprising: a) forming a first tantalum-comprising layer; and b) forming a second tantalum-comprising layer over the first tantalum-comprising layer, the second tantalum-comprising layer comprising nitrogen. In another aspect, the invention includes a method of forming a capacitor comprising: a) forming a first capacitor plate; b) forming a first layer over the first capacitor plate, the first layer comprising tantalum and oxygen; c) annealing the first layer in the presence of an ambient comprising a nitrogen-comprising gas containing at least one compound selected from a group consisting of ammonia, hydrazine and hydrazoic acid; the annealing forming a second layer over the first layer; and d) forming a second capacitor plate over the second layer.

Inventors

👤 Scott Jeffrey DeBoer
👤 F. Daniel Gealy
👤 Randhir P. S. Thakur

Bibliographic Details

Application Number —

Jurisdiction US

Data Source google_patents

Last Synchronized 2026-11-09 01:02

CPC Classifications

H; H10; H10P; H10P14/00; H10P14/60; H10P14/69; H10P14/692; H10P14/6938; H10P14/6939; H10P14/69393; H01; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/06; H01G4/08; H01G4/10; H10D; H10D1/00; H10D1/60; H10D1/68; H10P14/40; H10P14/418; H10P14/65; H10P14/6516; H10P14/6548; H10D1/682; H10D1/684; H10P14/6518; H10P14/6524; H10P14/6526; H10P14/6529; H10P14/6532; H10P14/6544

Claims Analysis

Total Claims: 54

Claim 1

Independent Claim 82 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a first layer as a dielectric over the first capacitor plate, the first layer comprising tantalum and having an exposed outer surface; forming a second layer over the first layer by exposing the outer surface of the first layer to a nitrogen-comprising gas comprising hydrazoic acid, NF 3 , or mixtures thereof, the second layer comprising tantalum and nitrogen; and forming a second capacitor plate over the second layer.

Claim 2

Independent Claim 82 words

Claim 3

Dependent Claim 14 words

The method of claim 1 wherein the nitrogen-comprising gas consists essentially of hydrazoic acid.

Claim 4

Dependent Claim 15 words

The method of claim 1 wherein the nitrogen-comprising gas consists essentially of NF 3 .

Claim 5

Dependent Claim 35 words

The method of claim 1 wherein the first layer comprises an outer surface and wherein the forming of the second layer comprises chemical vapor depositing a material comprising tantalum and nitrogen onto the outer surface.

Claim 6

Independent Claim 73 words

A method of forming a capacitor comprising: forming a first capacitor plate comprising polysilicon; forming a silicon nitride layer over the polysilicon; forming a first layer as a dielectric over the silicon nitride layer, the first layer comprising tantalum; forming a second layer over the first layer, the second layer comprising at least some of the tantalum of the first layer and nitrogen; and forming a second capacitor plate over the second layer.

Claim 7

Independent Claim 73 words

Claim 8

Independent Claim 87 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a first layer as a dielectric over the first capacitor plate, the first layer comprising tantalum and having an exposed outer surface; forming a second layer over the first layer by exposing the outer surface of the first layer to a nitrogen-comprising gas, the second layer comprising some of the tantalum of the first layer and some of the nitrogen of the nitrogen-comprising gas; and forming a second capacitor plate over the second layer.

Claim 9

Independent Claim 87 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a first layer as a dielectric over the first capacitor plate, the first layer comprising tantalum and having an exposed outer surface; forming a second layer over the first layer by exposing the outer surface of the first layer to a nitrogen-comprising gas, the second layer comprising some of the tantalum of the first layer and some of the nitrogen of the nitrogen-comprising gas; and forming a second capacitor plate over the second layer.

Claim 10

Dependent Claim 27 words

The method of claim 6 wherein the nitrogen-comprising gas comprises one or more gases selected from a group consisting of hydrazine, hydrazoic acid, NF 3 and ammonia.

Claim 11

Dependent Claim 13 words

The method of claim 6 wherein the nitrogen-comprising gas consists essentially of hydrazine.

Claim 12

Dependent Claim 14 words

The method of claim 6 wherein the nitrogen-comprising gas consists essentially of hydrazoic acid.

Claim 13

Dependent Claim 15 words

The method of claim 6 wherein the nitrogen-comprising gas consists essentially of NF 3 .

Claim 14

Dependent Claim 13 words

The method of claim 6 wherein the nitrogen-comprising gas consists essentially of ammonia.

Claim 15

Dependent Claim 22 words

The method of claim 6 wherein the exposure to the nitrogen-comprising gas comprises utilizing a plasma to generate an active nitrogen species.

Claim 16

Dependent Claim 28 words

The method of claim 6 wherein the exposing the outer surface of the first layer occurs at a temperature of from about 350° C. to about 900° C.

Claim 17

Dependent Claim 23 words

The method of claim 13 wherein the nitrogen-comprising gas comprises one or more gases selected from a group consisting of hydrazine and ammonia.

Claim 18

Dependent Claim 26 words

The method of claim 14 wherein the nitrogen-comprising gas consists essentially of hydrazine and wherein the temperature is from about 350° C. to about 600° C.

Claim 19

Dependent Claim 26 words

The method of claim 14 wherein the nitrogen-comprising gas consists essentially of ammonia and wherein the temperature is from about 600° C. to about 900° C.

Claim 20

Dependent Claim 12 words

The method of claim 6 wherein the second layer comprises tantalum nitride.

Claim 21

Dependent Claim 14 words

The method of claim 6 wherein the second layer comprises tantalum, oxygen and nitrogen.

Claim 22

Dependent Claim 20 words

The method of claim 6 further comprising forming a metal nitride between the second layer and the second capacitor plate.

Claim 23

Dependent Claim 25 words

The method of claim 19 wherein the second capacitor plate comprises TiN and is formed from one or more organic precursors comprising Ti and N.

Claim 24

Dependent Claim 25 words

The method of claim 19 wherein the second capacitor plate comprises WN and is formed from one or more organic precursors comprising W and N.

Claim 25

Dependent Claim 28 words

The method of claim 6 wherein the second capacitor plate comprises polysilicon and further comprising forming a metal nitride between the second layer and the second capacitor plate.

Claim 26

Dependent Claim 12 words

The method of claim 6 wherein the second capacitor plate comprises polysilicon.

Claim 27

Dependent Claim 11 words

The method of claim 6 wherein the first layer comprises oxygen.

Claim 28

Dependent Claim 17 words

The method of claim 6 wherein the first layer consists essentially of Ta 2 O 5 .

Claim 29

Dependent Claim 17 words

The method of claim 6 wherein the forming the second layer over the first layer is self-limiting.

Claim 30

Independent Claim 98 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a first layer as a dielectric over the first capacitor plate, the first layer comprising tantalum and having an exposed outer surface; forming a second layer over the first layer by exposing the outer surface of the first layer to a nitrogen-comprising gas at a temperature of from about 350° C. to about 900° C., and for a time of from about 30 seconds to about 10 minutes, the second layer comprising tantalum and nitrogen; and forming a second capacitor plate over the second layer.

Claim 31

Independent Claim 98 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a first layer as a dielectric over the first capacitor plate, the first layer comprising tantalum and having an exposed outer surface; forming a second layer over the first layer by exposing the outer surface of the first layer to a nitrogen-comprising gas at a temperature of from about 350° C. to about 900° C., and for a time of from about 30 seconds to about 10 minutes, the second layer comprising tantalum and nitrogen; and forming a second capacitor plate over the second layer.

Claim 32

Independent Claim 91 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a tantalum-comprising layer as a dielectric over the first capacitor plate, the tantalum-comprising layer comprising oxygen and being substantially void of carbon; forming a barrier layer over the tantalum-comprising layer; forming a metal layer comprising carbon over the barrier layer; forming a second capacitor plate over the metal layer; and processing the metal layer at a sufficient temperature to diffuse carbon from the metal layer, the barrier layer substantially preventing such carbon from diffusing into the tantalum-comprising layer.

Claim 33

Independent Claim 91 words

Claim 34

Dependent Claim 12 words

The method of claim 28 wherein the metal layer comprises metal nitride.

Claim 35

Dependent Claim 21 words

The method of claim 29 wherein the metal nitride layer comprises TiN or WN and is formed by chemical vapor deposition.

Claim 36

Dependent Claim 13 words

The method of claim 28 wherein the barrier layer comprises tantalum and nitrogen.

Claim 37

Dependent Claim 12 words

The method of claim 31 wherein the barrier layer comprises tantalum nitride.

Claim 38

Dependent Claim 14 words

The method of claim 31 wherein the barrier layer comprises tantalum, oxygen and nitrogen.

Claim 39

Independent Claim 68 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a tantalum-comprising layer as a dielectric over the first capacitor plate, the tantalum-comprising layer comprising oxygen; forming a barrier layer over the tantalum-comprising layer, the barrier layer comprising less than 10 volume percent of carbon and comprising some of the tantalum of the tantalum-comprising layer; and forming a second capacitor plate over the barrier layer.

Claim 40

Independent Claim 68 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a tantalum-comprising layer as a dielectric over the first capacitor plate, the tantalum-comprising layer comprising oxygen; forming a barrier layer over the tantalum-comprising layer, the barrier layer comprising less than 10 volume percent of carbon and comprising some of the tantalum of the tantalum-comprising layer; and forming a second capacitor plate over the barrier layer.

Claim 41

Dependent Claim 13 words

The method of claim 34 wherein the barrier layer comprises tantalum and nitrogen.

Claim 42

Independent Claim 93 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a first layer as a dielectric over the first capacitor plate, the first layer comprising tantalum and oxygen; annealing the exposed first layer in the presence of an ambient comprising a nitrogen-comprising gas containing at least one compound selected from a group consisting of ammonia, hydrazine, NF 3 and hydrazoic acid; the annealing forming a second layer over the first layer comprising some of the tantalum of the first layer; and forming a second capacitor plate over the second layer.

Claim 43

Independent Claim 93 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a first layer as a dielectric over the first capacitor plate, the first layer comprising tantalum and oxygen; annealing the exposed first layer in the presence of an ambient comprising a nitrogen-comprising gas containing at least one compound selected from a group consisting of ammonia, hydrazine, NF 3 and hydrazoic acid; the annealing forming a second layer over the first layer comprising some of the tantalum of the first layer; and forming a second capacitor plate over the second layer.

Claim 44

Dependent Claim 16 words

The method of claim 36 wherein the nitrogen-comprising gas is within a plasma during the annealing.

Claim 45

Dependent Claim 29 words

The method of claim 36 wherein the nitrogen-comprising gas consists essentially of hydrazine and wherein the annealing comprises a temperature of from about 350° C. to about 600° C.

Claim 46

Dependent Claim 29 words

The method of claim 36 wherein the nitrogen-comprising gas consists essentially of ammonia and wherein the annealing comprises a temperature of from about 600° C. to about 900° C.

Claim 47

Independent Claim 89 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a first layer as a dielectric over the first capacitor plate, the first layer comprising tantalum and having an exposed outer surface; forming a second layer over the first layer by exposing the outer surface of the first layer to a nitrogen-comprising gas consisting essentially of hydrazine at a temperature of from about 350° C. to about 600° C., the second layer comprising tantalum and nitrogen; and forming a second capacitor plate over the second layer.

Claim 48

Independent Claim 89 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a first layer as a dielectric over the first capacitor plate, the first layer comprising tantalum and having an exposed outer surface; forming a second layer over the first layer by exposing the outer surface of the first layer to a nitrogen-comprising gas consisting essentially of hydrazine at a temperature of from about 350° C. to about 600° C., the second layer comprising tantalum and nitrogen; and forming a second capacitor plate over the second layer.

Claim 49

Independent Claim 89 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a first layer as a dielectric over the first capacitor plate, the first layer comprising tantalum and having an exposed outer surface; forming a second layer over the first layer by exposing the outer surface of the first layer to a nitrogen-comprising gas consisting essentially of ammonia at a temperature of from about 600° C. to about 900° C., the second layer comprising tantalum and nitrogen; and forming a second capacitor plate over the second layer.

Claim 50

Independent Claim 89 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a first layer as a dielectric over the first capacitor plate, the first layer comprising tantalum and having an exposed outer surface; forming a second layer over the first layer by exposing the outer surface of the first layer to a nitrogen-comprising gas consisting essentially of ammonia at a temperature of from about 600° C. to about 900° C., the second layer comprising tantalum and nitrogen; and forming a second capacitor plate over the second layer.

Claim 51

Independent Claim 82 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a first layer as a dielectric over the first capacitor plate, the first layer comprising tantalum and oxygen; annealing the exposed first layer at a temperature of from about 350° C. to about 600° C. in the presence of an ambient comprising a nitrogen-comprising gas consisting essentially of hydrazine, the annealing forming a second layer over the first layer; and forming a second capacitor plate over the second layer.

Claim 52

Independent Claim 82 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a first layer as a dielectric over the first capacitor plate, the first layer comprising tantalum and oxygen; annealing the exposed first layer at a temperature of from about 350° C. to about 600° C. in the presence of an ambient comprising a nitrogen-comprising gas consisting essentially of hydrazine, the annealing forming a second layer over the first layer; and forming a second capacitor plate over the second layer.

Claim 53

Independent Claim 82 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a first layer as a dielectric over the first capacitor plate, the first layer comprising tantalum and oxygen; annealing the exposed first layer at a temperature of from about 600° C. to about 900° C. in the presence of an ambient comprising a nitrogen-comprising gas consisting essentially of ammonia, the annealing forming a second layer over the first layer; and forming a second capacitor plate over the second layer.

Claim 54

Independent Claim 82 words

A method of forming a capacitor comprising: forming a first capacitor plate; forming a first layer as a dielectric over the first capacitor plate, the first layer comprising tantalum and oxygen; annealing the exposed first layer at a temperature of from about 600° C. to about 900° C. in the presence of an ambient comprising a nitrogen-comprising gas consisting essentially of ammonia, the annealing forming a second layer over the first layer; and forming a second capacitor plate over the second layer.

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USPTO Annuity & Maintenance Windows

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2003-11-14	2004-05-15	2004-11-14	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2007-11-14	2008-05-15	2008-11-14	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2011-11-14	2012-05-15	2012-11-14	$7700.00	Window Closed / Lapsed

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